I've been working on a custom process template for a client in TFS and came across some things that I didn't know. Now I am not an Analysis services guy so this was a little new to me. It took me forever to find decent definitions on how to correctly set "reportable" in TFS.
The docs on this, how to use it, and what it should be set to, etc can be a bit tricky to find. It wasn't until I picked up Professional Team Foundation System that I got a clear answer. After a little bit of tinkering and some quick pivot tables in Excel, I became an OLAP master. Now that is a total fabrication and basically a tall tale. I do highly recommend this book to those using TFS.
The TFS SDK documenation has a decent description on what the settings can be and what they mean.